Editorial

An endangered city

Stem Dhaka's groundwater depletion

It is with trepidation that we take note of the findings about the alarming rate at which the capital city's groundwater level is dropping. Presented at a press conference in the city, a group of local researchers revealed that the water level in the capital city has dropped 170 feet below the sea level. Evidently, unplanned extraction of groundwater is to blame.

As we know it, fast depletion of groundwater level triggers land subsidence or accelerates the rate at which land subsides naturally following changes in tectonic plates. In a study conducted at the Dhaka University Earth Observatory Centre, researchers have found that Dhaka's landmass is dropping by 13.91 millimetres a year. One can easily imagine the disaster waiting to happen should the groundwater level is allowed to continue to deplete at the present rate.

The gravity of the situation calls for a solution on an emergency footing. Reasons behind this have already been identified. In the backdrop of surface water pollution by industrial and household waste, 83 percent of the water supplied to about 15 million city dwellers is pumped from underground. However, the rate at which rain recharges groundwater is far outstripped by the extraction rate.

Therefore, in order to address the challenge urgently, first the decision-makers will have to scale down extracting groundwater. They'll have to make sure that surface water sources i.e. rivers and canals are utilized to meet the demands of city dwellers. Secondly, they'll have to focus on saving our water bodies by fending off pollution and water body grabbers. Then all the surface water treatment plants that have been in the offing will have to materialize.

Simultaneously, rainwater harvesting on rooftop and in other potential reservoirs seems to be an answer. Rooftops of buildings have to be designed and built in a certain way to make use of this option. Rajuk has to incorporate this measure in the amendment to the Bangladesh National Building Code and see to it that it is enforced properly in all the new buildings. If possible, owners of old buildings should also be encouraged to redesign their rooftop in the same way.

But when will we wake up? After the ground underneath our feet slips away, or what?